Many compounds and their derivatives have been found to be useful to prevent diabetic cataract, nerve tissue damage and certain vascular changes associated with diabetes mellitus. It is believed that the usefulness of some of these compounds correlates with their observed effect on aldose reductase activity. The inhibition of the enzyme aldose reductase or related enzymes results in the inhibition of abnormal polyol accumulation at the expense of NADPH in those tissues containing aldose reductase and/or related aldehyde reductases. The inhibition of the formation of a polyol such as sorbitol or galactitol, arising from the reduction of an aldose, such as glucose or galactose respectively, is believed to be beneficial in delaying the progression of certain complications arising from hyperglycemia and hypergalactocemia. Hyperglycemia is associated with the complications of neuropathy, nephropathy, retinopathy, cataract, glaucoma and impaired wound healing in persons suffering from diabetes mellitus.